Isolation of prostrate turfgrass mutants via screening of dwarf phenotype and characterization of a perennial ryegrass prostrate mutant

Abstract

Prostrate turf varieties are desirable because of their increased low mowing tolerance, heat resistance, traffic resistance and ground coverage compared with upright varieties. Mutation breeding may provide a powerful tool to create prostrate varieties, but there are no simple, straightforward methods to screen for such mutants. Elucidation of the molecular basis of the major ‘green revolution’ traits, dwarfism and semi-dwarfism, guided us to design a simple strategy for isolating dwarf mutants of perennial ryegrass (Lolium perenne L.). We have shown that gamma-ray-mediated dominant dwarf mutants can be easily screened for at the three-leaf stage. About 10% of dwarf mutant lines also displayed a prostrate phenotype at mature stages (>10 tillers). One prostrate line, Lowboy I, has been characterized in detail. Lowboy I had significantly shorter canopy, leaf blade and internode lengths compared with wild type. Lowboy I also exhibited greater tolerance to low mowing stress than wild type. Exogenous gibberellic acid (GA) restored Lowboy I to a wild-type phenotype, indicating that the dwarf and prostrate phenotypes were both due to GA deficiency. We further showed that phenotypes of Lowboy I were dominant and stably inherited through sexual reproduction. Prostrate turfgrass mutants are difficult to screen for because the phenotype is not observed at young seedling stages, therefore our method represents a simple strategy for easily isolating prostrate mutants. Furthermore, Lowboy I may provide an outstanding germplasm for breeding novel prostrate perennial ryegrass cultivars.

Transcriptome profiles reveal that gibberellin-related genes regulate weeping traits in crape myrtle

“…The weeping (we1) gene, which is an ortholog of Arabidopsis SCR, and weeping2 (we2), an ortholog of Arabidopsis SHR, were identified in a gravitropic Japanese morning glory mutant with defective endodermal cells 51,52 . Exogenous GA treatment was found to rescue prostrate ryegrass mutants to a wild-type phenotype, implying that the prostrate and dwarf phenotypes are both caused by GA deficiency 53 .…”

Transcriptional Profiling and Identification of Heat-Responsive Genes in Perennial Ryegrass by RNA-Sequencing

“…It does not withstand hot weather, and high temperature is a major factor limiting its performance in warmer and transition regions (Turgeon, 2011). Some studies of perennial ryegrass under heat stress have been conducted, but they are typically focused on breeding new cultivars, growth, or the physiological and biochemical aspects of the plants’ response (Minner et al, 1983; Sugita, 1991; Jiang and Huang, 2001; Kauffman et al, 2007; Zhang et al, 2013; Barnes et al, 2014; Chen et al, 2016; Wang and Xiong, 2016). To date, data regarding the molecular mechanism of perennial ryegrass responding to heat stress is very limited.…”

Morphological Characteristics and Productivity of Guinea Grass (Panicum maximum CV Purple Guinea) Irradiated with Gamma-Ray

“…The population of M1V1 Guinea grass was affected by gamma irradiation. The increased production due to gamma irradiation in M1V1/ M2 was also reported in ryegrass (Chen et al, 2016 ), peas (Khan, 2018), lentil beans (Tabti et al, 2018), Sesamum indicum L (Muhammad et al, 2018), and wheat (Ahmed, 2017). Each type of plant has a certain dose of irradiation in increasing its productivity.…”

“…The control plant height in the M1 population was higher than the Gamma irradiated plant. The decreased plant height due to gamma-ray irradiation on M1 was also reported to occur in maize (Marcu et al, 2013), soybeans (Alikamanoglu et al, 2011), Curcuma alismatifolia (Taheri et al, 2014), Arabidopsis thaliana (Kim et al, 2014), Phaseolus vulgaris (Ulukapi & Ozmen, 2018), ryegrass (Chen et al, 2016), Okra (Amir et al, 2018) Table 6. Phenotypes variance (σ2p), genetic variance (σ2g), heritability (h2) and genetic coefficient variation (GCV) of shoot fresh weight and dry weight, tiller, leaf weight, length of root and weight of roots in M1V2 population…”